D R Horton Refuses to Warranty Plumbing Leak Damage Under Warranty Conroe, Texas

We own a home in Water Crest on Lake Conroe (Conroe, Texas). We are approaching our 2-year anniversary/closing date at the end of this month. On November 4th, we discovered there has been a significant leak in the water filtration system at/under the kitchen sink (which was a "standard” feature as per the documents we signed). The leaking water caused mold to grow in an approximate ten-foot section of the under-sink cabinet walls. There is a two-year DRH warranty for plumbing systems. As of today, DRH’s warranty department has REFUSED to do anything, as they "point the finger” at their water filter system supplier. The water filtration system supplier has stated the water filter is only warrantied through their company for one year. Basically, neither D R Horton or the water filter supply company D R Horton hired to install the system at the sink accept any liability. We have incurred more than $3,000 out of our personal money paying for remediation and reconstruction. This does not include our personal time hiring the work and being home while it is being done. Why would D R Horton’s warranty representative dismiss our warranty issue and accuse us of "threatening DRH on social media” when we clearly stated we would not post about this issue if DRH reimburses us for only the cost of remediation and reconstruction? Is negative publicity worth the $3,000 DRH should reimburse us for what we consider a warranty issue?